package net.octopeer.utilities;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * SimpleSHA1 is used to identify SimpleSHA1 hash creator class
 */
public class SimpleSHA1 { 
    private static String convertToHex(byte[] data) {
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < data.length; i++) {
        	int halfbyte = (data[i] >>> 4) & 0x0F;
        	int two_halfs = 0;
        	do {
	            if ((0 <= halfbyte) && (halfbyte <= 9))
	                buf.append((char) ('0' + halfbyte));
	            else
	            	buf.append((char) ('a' + (halfbyte - 10)));
	            halfbyte = data[i] & 0x0F;
        	} while(two_halfs++ < 1);
        }
        return buf.toString();
    }
 
    /**
     * 
     * @param text
     * @return
     * @throws java.security.NoSuchAlgorithmException
     * @throws java.io.UnsupportedEncodingException
     */
    public static String SHA1(String text) throws NoSuchAlgorithmException, UnsupportedEncodingException  {
	MessageDigest md;
	md = MessageDigest.getInstance("SHA-1");
	byte[] sha1hash = new byte[40];
	md.update(text.getBytes("iso-8859-1"), 0, text.length());
	sha1hash = md.digest();
	return convertToHex(sha1hash);
    }
}
